The present disclosure herein relates to a semiconductor memory device, and more particularly, to the controlling of a sense amplifier source node in a semiconductor memory device such as a dynamic random access memory.
Semiconductor memory devices such as dynamic random access memories (hereinafter referred to as “DRAMs”) have been widely used as main memories in electronic systems including computers and portable electronic devices.
A DRAM, almost by necessity, includes a bit line sense amplifier that detects and amplifies data stored in a memory cell.
The active operation of a DRAM, for example, a read operation mode or a write operation mode inevitably consumes a power for accessing data. In the case where data access is not performed, for example, in an operation that is not active, a DRAM may have a power down mode for minimally consuming driving current. In order to further reduce power consumption, a DRAM may receive a power down command from a controller even during active operation, which is commonly referred to as an active power down command.
However, even in the case of an active power down mode, leakage current may continue to flow to a bit line sense amplifier. Thus, power is still consumed.